Seiji Sakaguchi (坂口征二,Sakaguchi Seiji, born February 17, 1942) is a retired Japanese professional wrestler and judoka, Sakaguchi holds a 7th dan red and white belt in Judo. Sakaguchi was a mainstay of New Japan Pro Wrestling and also competed for the World Wide Wrestling Federation and the National Wrestling Alliance. His sons are professional wrestler and mixed martial arts fighter Yukio Sakaguchi and television actor Kenji Sakaguchi. Sakaguchi currently works for New Japan as an advisor.[1]

Before becoming a professional wrestler, he was a judoka with a fifth degree black belt and won the 1965 All Japan Judo Championship. Coach Koji Sone was accused by Anton Geesink's teammates in the 1965 World Judo Championships of having Sakaguchi throw the match against the more rested Matsunaga in order to allow Matsunaga take on the weary Geesink in the final round.[2]